data_global
_chemical_name_mineral 'Downeyite'
loop_
_publ_author_name
'Stahl K'
'Legros J P'
'Galy J'
_journal_name_full 'Zeitschrift fur Kristallographie'
_journal_volume 202 
_journal_year 1992
_journal_page_first 99
_journal_page_last 107
_publ_section_title
;
 The crystal structure of SeO2 at 139 and 286 K
 Note: T = 139 K
;
_database_code_amcsd 0011027
_chemical_compound_source 'Synthetic'
_chemical_formula_sum 'Se O2'
_cell_length_a 8.3218
_cell_length_b 8.3218
_cell_length_c 5.0541
_cell_angle_alpha 90
_cell_angle_beta 90
_cell_angle_gamma 90
_cell_volume 350.008
_exptl_crystal_density_diffrn      4.211
_symmetry_space_group_name_H-M 'P 42/m b c'
loop_
_space_group_symop_operation_xyz
  'x,y,z'
  '1/2-y,1/2-x,1/2+z'
  '1/2+y,1/2+x,1/2-z'
  'y,-x,1/2-z'
  '-y,x,1/2+z'
  '1/2+x,1/2-y,z'
  '1/2-x,1/2+y,-z'
  'x,y,-z'
  '-x,-y,z'
  '1/2+y,1/2+x,1/2+z'
  '1/2-y,1/2-x,1/2-z'
  '-y,x,1/2-z'
  'y,-x,1/2+z'
  '1/2-x,1/2+y,z'
  '1/2+x,1/2-y,-z'
  '-x,-y,-z'
loop_
_atom_site_label
_atom_site_fract_x
_atom_site_fract_y
_atom_site_fract_z
_atom_site_U_iso_or_equiv
Se   0.13396   0.20929   0.00000   0.00570
O1   0.13752   0.36248   0.25000   0.00937
O2  -0.05789   0.17358   0.00000   0.01140
loop_
_atom_site_aniso_label
_atom_site_aniso_U_11
_atom_site_aniso_U_22
_atom_site_aniso_U_33
_atom_site_aniso_U_12
_atom_site_aniso_U_13
_atom_site_aniso_U_23
Se 0.00428 0.00540 0.00732 0.00018 0.00000 0.00000
O1 0.00919 0.00919 0.00964 0.00193 0.00217 0.00217
O2 0.00596 0.01284 0.01524 -0.00137 0.00000 0.00000